Chronic kidney disease (CKD) is now recognized as a major public health problem. When the kidneys fail, death inevitably ensues without the aid of dialysis or kidney transplantation. It has long been recognized that African Americans are much more likely to experience end-stage renal disease (ESRD). In fact, African Americans are 4 times more likely to enter dialysis than whites. Hispanics are also at increased risk of ESRD, and are 1.7 times more likely to enter dialysis. Our previous research demonstrates that a driving force behind the increased rate of ESRD among African Americans is more rapid loss of kidney function in a larger proportion of the African American population. This application proposes a study to understand the reasons for this rapid disease progression among African Americans, and will expand our analysis to Hispanics. Our focus will be on risk factor control and clinical care provided for diabetes and hypertension, which together account for almost three-fourths of all ESRD in the U.S. To this end, we propose a retrospective cohort study of 2.7 million patients within a large managed care system. This cohort demonstrates the well-known disparity in ESRD rates despite equal access to health care benefits. Our unique study setting permits further control for differences in age, gender, and health insurance, and allows for extensive data capture using electronic health record systems, thereby allowing us to focus on disease burden, risk factor control, and the management of chronic disease according to established clinical practice guidelines. We will examine the time to ESRD and death from different starting points defined by kidney function, as measured by estimated glomerular filtration rate (eGFR). We will also examine the rate of change in kidney function. Variables that represent the risk factors and clinical management associated with diabetes, hypertension, and advanced CKD will be tested for their ability to explain: (1) ESRD and death, (2), the rate of change in kidney function, and (3) the differences between African Americans, Hispanics, and other racial/ethnic groups in ESRD, death, and the rate of change in kidney function. The insights gained from this proposed study are critical to determine the next steps of research to understand the root causes of the racial/ethnic disparities in ESRD, and what can be done to address disparities with the context of existing medical care. This project has the potential to benefit African Americans, Hispanics, and all other persons at high risk of CKD. Moreover, the results of this study will provide a useful benchmark for comparisons of ESRD disparities among insured and uninsured populations in the U.S. PUBLIC HEALTH RELEVANCE: Chronic kidney disease is now recognized as a major public health problem in the U.S. This research will advance knowledge about how to eliminate racial/ethnic disparities in end-stage renal disease (ESRD, which includes dialysis and transplantation), particularly among African Americans and Hispanics, who are at the highest risk of kidney failure.